This is a Rectify Series drop-in speaker system for Atlas Master (QSI-era) GP38/40 and possibly other QSI-era locomotives. More than just a box, the enclosure features Diapasonic Tuning™, which allows the lower frequencies to accurately develop and resonate, clears the midrange of excess resonance and tunes the upper-mid/high response. No modifications are needed to replace the factory speaker. Simply remove the two screws holding the stock speaker housing to the frame, remove the rear headlight PCB from the speaker housing, install the SSS system with a touch of adhesive, screw the rear headlight PCB onto the SSS system and conect the speaker.
The speaker comes fully assembled and tested.
Dimensions are: 30mmH x 18mmW x 33mmL